Review: MISSION TO MARS
Okay, enough grandstanding. Here's some science stuff.
[Note (added February 28, 2001): about half the population of this planet has emailed me about the scene in this movie involving the M&Ms representing DNA. One of the astronauts has them floating in front of him while en route to Mars, and they form a spiral pattern. He claims it's the DNA of the perfect woman (and I think he was just making a joke, despite the brutal beating biology takes in this movie). Anyway, the email I get complains that the entire spiral is rotating, which is impossible in microgravity. When I saw the movie, I didn't notice this. It looked to me like the M&Ms were spinning individually. The only way for me to verify that would be to see the movie again. That is not going to happen, so this will have to remain a mystery. Stop emailing me! ;-)]
Bad: It's stated early on in the movie that married couples have been shown to be the best for long voyages.
Good: Actually, I don't think NASA or any other space agency has worked on that yet. I personally have my doubts. It sounds good on the surface; a married couple has had years to work on how to communicate and how best to deal with the other person. However, a space voyage has a hierarchy of command, and a married couple's interaction might interfere with that. It's difficult to know how this would work, and I would guess that only time and experimentation will tell.
Incidentally, I have grave doubts about having a happily married couple on board a ship where the other two astronauts are (a) a clearly horny young man and (b) a man who is still grieving for his dead wife. How does it feel to see a happy couple dancing in zero-g knowing your own wife is dead? That doesn't make for a terribly happy ship. Also, somehow, seeing such a happy couple takes away from the seriousness of the mission: they're going to rescue friends that may very well be dead.
Bad: We see a rover moving over the landscape of Mars. The land is cracked and dry.
Good: Mars is certainly dry, but it wasn't always that way. Water may have flowed many millions of years ago. However, the rover is going over landscape that looked to me (and at least one other astronomer friend of mine) like a dry lake bed. Remember, it's been a long time since water stood around on Mars, and Mars has weather. Those cracks would have been filled in by dust and rock hundreds of thousands of years before. The writers were trying to show how desolate and dry Mars was, but they picked a poor example. However, I will say that the rest of the landscape of Mars was very well done in the movie. I really felt like this is the way would look if I were there.
Good: NASA would never allow all four astronauts to be away from the base camp at one time. Any sort of problem back home could have devastating results: a puncture in the wall, a problem with the greenhouse, anything, and all four could die. Also, any catastrophe like a broken rover could strand them kilometers from base. There would be someone at base at all time. Not astronomy, but come on. Common sense.
Case in point: you are standing at a mountain on another planet while said rock is emanating some weird signal. Suddenly, a huge tornado comes up and aims for your men. In my opinion, it's time to leave! But they all just stand there, waiting for the plot device to kill them. Need I say it? Yuck.
Good: Well, having a spinning space station is a great idea, since long term exposure to zero gravity has bad effects on the human body, like deterioration of bone calcium. The spin of the wheel provides an inward force, which feels like gravity. However, there is no way we'll have such a station in 20 years. I hate to say it, but the space station being built now won't have one, and I doubt 20 years will change that; it takes that long to plan out how to do it! For example, the Space Shuttle program dates back to the 1970s. Nothing like a spinning wheel is on the books now.
Incidentally, one of the controllers shown in that scene is none other than Story Musgrave, astronaut extraordinaire. He has flown on six Shuttle missions, and holds several advanced degrees. That was pretty cool to have him there.
Bad: As the second mission approaches Mars, we see a dust storm covering nearly half the planet.
Good: This part is actually correct; Mars is prone to global storms. In 1971, NASA sent the probe Mariner 9 to Mars, and when it got there the entire planet was enveloped in a storm. Eventually, the storm dissipated and a lot of very useful information was returned.
Bad: When the second mission goes for orbital insertion, a meteoroid impact punctures holes in the hull and the fuel lines. The astronauts search for the holes by pouring out a Dr. Pepper container; the liquid goes toward the hole, leaks outside the ship and freezes in place.
Good: When the meteoroid punctures the hull, we don't understand what happens at first. I like that; an impact is likely to happen at a relative speed of many kilometers per second, and the rock would move through the width of the ship in a few milliseconds. It would be as if holes appeared by magic. Anyway, any problems with the intrusive product placement aside, the Dr. Pepper wouldn't freeze so quickly. It is cold near Mars, but not that cold. The liquid has to get rid of its internal heat, and the only way to do that in the vacuum of space is to radiate it away, which is a very inefficient and slow process. Ironically, the soda would actually boil, because in a vacuum liquids can boil at room temperature (that's why some recipes need to be modified for people at high altitudes; water boils at a lower temperature in the lower air pressure at such heights). The soda would be warm enough initially to actually boil. The boiling would cause it to dissipate pretty rapidly once it hits vacuum; the astronaut outside the ship would have seen the spray of steam, not the icicles.
[Note added May 31, 2001: Bad reader Jay Coleman pointed out to me that a meteoroid that small would most likely vaporize when it hit the hull, and not punch through. I think he may be right; it would take a larger mass to actually make it through. Actually, in real life, small meteoroids are dangerous to satellites not because of impact, but because the heat of impact vaporizes the metal in the satellite, and the ionized plasma then wreaks havoc on the electronics!]
Another point in that scene: think of how many times the typical Space Shuttle launch is delayed due to some sort of tiny leak or another; there are sensors everywhere, including on-board, to find any potential leak. Yet on the Mars ship the fuel line has multiple holes, fuel is leaking everywhere (and freezing again, oops), yet not a single alarm goes off. This is a plot device, of course: they need the ship to be disabled, so they have the back end blow off. Which brings me to:
Good: Mars is smaller than the Earth, but it's still a lot of real estate. Orbital space around Mars is big, and the odds of the resupply ship being within a thousand kilometers is small enough, let alone only one kilometer away. I am willing to believe the ship was going to go in a similar orbit as the resupply ship, but you don't do tricky orbital maneuvers when another object is that close! It's asking for potential collisions. When NASA sends up a Shuttle to service a satellite on orbit (such as Hubble), they make sure they attain orbit very far away, then spend many hours approaching the satellite. A collision up there can kill the astronauts and ruin a very expensive machine (or two).
Then it gets worse. Remember, the ship never made it into orbital insertion. There are many ways of getting to Mars, but no matter how you do it you need to change your speed a lot to arrive safely (for some approaches you need to move faster, and for others you need to slow down; it was never specified in the movie what kind of approach they were doing). They should have been moving many hundreds or thousands of kilometers per hour relative to the REMO, not just a few kilometers per hour. It's said specifically in the movie that suit jets are for attitude control and not real velocity. They would never have a chance to catch the REMO.
Bad: Astronaut Woody Blake moves ahead of the others to catch up to the REMO. He latches the hook, but fails to hang on. He slides past. His wife Terri Fisher tries to save him using her own suit jets, and fires them for some time. When her tanks reach 50% fuel she stops firing, and gives a short burst to stop, too short to save her husband.
Good: On Earth, we are accustomed to having to apply force constantly to stay moving. We have to pedal bikes to go, and we have to hold the gas pedal down in a car or else we will eventually slow to a stop. That's due to friction; the parts of the bike or car rub and the wheels rub against the ground. Eventually that robs the vehicle of its forward motion.
Space is a vacuum. There is no friction! Out there, you are ruled by Newton's second law: as long as you apply a force, you accelerate. Astronaut Fisher fired her jets for a long time, and would have accelerated all that time. She couldn't kill her forward velocity by a short burst! She would have to turn around and fire for just as long just to stop! Then she would have to continue firing to get back to the REMO. Both my friends and I laughed out loud when that happened in the movie.
Bad: It becomes clear that Blake will die, and no one can save him. He knows his wife will try, even though it might kill her too. To save her, he kills himself by taking his helmet off. Instantly, he freezes, and his face becomes distorted and icky.
Good: Again, he wouldn't freeze that fast. The human body holds a lot of heat, and it would take a long time to freeze. Have you ever found yourself literally freezing solid when you go outside on a winter's day? No, of course not. Yet losing heat by transferring it to cold air is far faster than doing so by simply radiating it away, as you would in space. If it takes a long time in frigid air, it would take even longer in frigid space.
His face would not get icky, either; at least, not right away. There is no
air in space. Despite what movies like ``Outland'' would have you believe,
you wouldn't explode if exposed to space. The air would rush out of your
lungs explosively, which could damage your lungs and throat. But your
skin and vascular system would contain your blood fairly well, protecting
it against the vacuum, so your blood would not boil. After a long time,
the cells would freeze, and the expanding ice crystals (water expands
when it freezes) would rupture the cells, making you look a pretty good
mess. But that would take hours, or longer, not seconds. Oddly though,
a human can survive several seconds of pure vacuum. ``2001: A Space
Odyssey'' had a scene like this; the astronaut had to go from his pod
to the airlock without his helmet. I don't think he would look as nicely
coiffed after the incident as he did in the movie, but the scene was largely
accurate. Ironically, as Arthur C. Clarke has pointed out, in Earth orbit,
your biggest problem is sunburn! Exposure to the UV light of the Sun would
fry your skin in minutes, giving you a very bad sunburn. I'd be satisfied
to live with that, given the alternative! For more info about what happens
when a human is exposed to a vacuum, read the Imagine the Universe! website. They have real-life examples
discussed too. Very cool.
[Oops! (June 2, 2000) Sometimes when I write I get in such a furor that I forget what I originally meant to say. The next Bad/Good is a case in point. I originally meant to say that the fabric would not blow in the wind because of the large amount of pressure on it, but somehow wrote that the fabric would tear under that pressure. That's not true. As a matter of fact, NASA is investigating using an inflatable living quarters for the space station! So I apologize for losing my way. You may read the next paragraph, but bear in mind I was wrong.]
Bad: When the second mission goes to the first mission's base camp, they find the greenhouse. It is made of fabric, with the fabric blowing in the wind.
Good: Mars has an atmosphere, but it's exceedingly thin. At best it's about 0.009 times the pressure of Earth's. Even if we allow that inside the greenhouse the pressure was 0.1 times Earth normal, that's a huge amount of pressure on the fabric. The reason a balloon has a taut surface is that the air inside is under pressure, and pushes outwards on the fabric, stretching it. Too much pressure, and pop! The balloon bursts. The same would happen to the greenhouse fabric. Normal pressure on the Earth is about one kilogram per square centimeter (15 pounds per square inch). Multiply that by the number of square centimeters of fabric, and you'll see there is a huge amount of force on the fabric. It would rip to shreds as soon as it was inflated.
Bad: Terri Fisher worries that astronaut Luke Graham, stranded on Mars for many months, has gone insane. She says ``Long term exposure to low gravity can have an adverse affect on the brain.''
Good: She's wrong. Astronauts have stayed aboard Mir at essentially zero gravity for many months at a time, yet they appear to remain quite sane. None has ever publicly admitted to seeing an alien Face on Mars, at least.
Good: Actually, this part was clever. I was expecting
the same old NASA cover up junk, but they were smart.
Bad: The astronaut Luke Graham spends a lot of time studying the Face, and determines that the signal it gave off shows DNA if decoded the right way. Terri Fisher says``That's human DNA.''
Good: How did she know? As she said a moment later, chimp DNA is almost exactly like ours. So how did she recognize it? Also, Luke spent months working on this and never figured out it was a test, yet astronaut Jim McConnell figures it out in a few minutes. Bleach.
Bad: The astronauts decide to complete the test and activate the Face. Astronaut Phil Polymer stays behind to install the repair hardware in the return vehicle.
Good: Um. I think it might be best to make sure the return vehicle works first before tinkering with a millions-of-years-old alien artifact. But that's just me.
Bad: The astronauts activate the Face, see a solar system model, and are warmly greeted by a humanoid alien hologram of some advanced sort, which shows them their history. A giant impact devastated Mars in the distant past, so they had to leave. They go to a different galaxy, but stop long enough to seed Earth with life. Life evolves, and eventually turns into humans.
Good: Oh, barf. First, this idea has been done to death in science fiction, and usually a lot better! Still, let's go with it. The aliens seed Earth with life. Why? The model clearly shows a blue, warm Earth. Why not colonize it? It's only a few million kilometers away! At least go to some star system in our own Galaxy! Nope. Instead, they opt to go a few million light years to some other galaxy. I assume the writers fell for the old ``solar system/galaxy'' confusion that commonly plagues newscasts.
Luke says that this explains the Cambrian Explosion, a burst of evolution that occurred about 600 million years ago on Earth. That sets the date for the martian catastrophe, and the date the Face was built. That's certainly enough time for the Face to get covered by dirt. Yet, the simulation they are shown clearly shows humans. Were the martians watching us all this time? That seems logical. Then why did they kill the first astronauts?! The Face is an intelligence test. However, if we're smart enough to get to Mars, I think we deserve the right to find out who we are! Why kill us after we go all that way?
The movie was stealing from an excellent short story by Arthur C. Clarke called ``The Sentinel'', where an alien artifact on the Moon is found by men. They tinker with it, and it sends a signal to deep space. Clearly, it was designed to send a signal to the aliens when we found it, indicating we had finally become intelligent enough for space travel, alerting the aliens to our status. This story was the basis of ``2001''. Having the aliens kill the astronauts in ``Mission to Mars'' was simply gratuitous.
Bad: Jim McConnell decides to take the alien ship to meet his makers, so to speak. He steps in a tube, and it fills with some fluid. He finds he can breathe it, and away he goes to another galaxy, which the other departing astronauts see from their return vehicle.
Good: Oh, barf again. This steals from ``2001'', ``Close Encounters'', and ``The Abyss''. This isn't an astronomy complaint, just one as a person who has actually seen movies once or twice before in my life. At least they could try stealing from more obscure movies! But here is an astronomy mistake: there are no other galaxies you can see easily. The Andromeda Galaxy can be seen to the naked eye from a dark site, but it looks like a fuzzy blur. The galaxy in the movie had well defined spiral arms, which would be completely invisible to the other astronauts. This may seem like a nitpick, but in an ending that sappy and overdrawn I don't feel like being lenient.
So, do you get the impression I didn't like the movie? ;-) As I said in the intro, the mistakes weren't all that huge, and some of the movie was actually clever. But overall I thought it was really bad.
Having said that, let me say something else: the plan they used to get to Mars struck me as being very clever, and a good idea. They send a team first to set things up, as well as robotic supply vehicles. A second team is sent to follow up with more supplies, and so on. This plan was also familiar, so I wasn't surprised to see Robert Zubrin listed as a technical advisor on the movie. He is the author of the ``Mars Direct'' plan, which is basically a quick and easy way to get to Mars. His plan is controversial; many space experts think it won't work. I have serious doubts as well. I reviewed his book ``Entering Space'' for the February 2000 issue of Astronomy magazine, and I found most of his engineering plans to be good, but some were a bit shaky, as were his philosophical arguments for why we need to colonize space. Either way, his ``Mars Direct'' is an interesting and exciting basic plan to get to Mars, and indeed when we do it for real, it might be the working model of the actual method employed.
There are lots of Mars websites that might be of interest.